Is Zakah (obligatory charity) due on articles of merchandise even if they were stacked in the merchant`s stores for years?
                                Yes, Zakah is due on goods even if they were stacked in merchant`s stores for years, in this manner Islam struggle against monopoly.
                             
                        
                            
                                
                                A pious man proposed to me and my father was hesitant in this regard because he is black, am I sinful if I accepted his proposal?
                                If the suitor is pious, color isn`t a drawback. However, try talking to your father kindly, so that he approves of your marriage with contentment, and that is better for you.
                             
                        
                            
                                
                                If someone bought a car from an interest-based bank and then sold it to another person, does the second person bear any sin if they use the car's price to pay the installments owed to the bank?
                                When the buyer purchased the car, it became their property, and the price became their responsibility. The bank acts as the seller's agent for receiving the payment. Therefore, there is no sin on the second buyer, God willing, as long as the bank does not impose an increase in the amount if a payment is delayed. And Allah The Almighty Knows Best.
                             
                        
                            
                                
                                Is it permissible for the guardian, or the father of the child to hit the latter in order to teach him/her good manners?
                                It is permissible for the guardian to hit his/her child for teaching them good manners once they become ten years old provided that it is done mildly, harmlessly and without intimidation. Actually, such punishment is to be employed gradually i.e. after: asking, warning, and scolding. As for the teacher, he isn`t allowed to hit the student unless the latter`s father approves of it, and it is done according to necessity without intimidation, or harm.